"When we got on scene, we had reports that there were children inside," fire department Maj. Tammy McKinney said, according to the Associated Press. "The fire was so intense that we could not make entry and had to knock the fire down before we could make entry. That's when we found the bodies."

The Oklahoman reported that a space heater had been sitting too close to flammable material and touched off the fire.

KOTV reported that there were no working smoke detectors in the house. The TV station also reported that the house had not had any gas service since 2008.

Davd Ruppert, who rented a room at the house and escaped the flames, told the AP that the children typically stayed with their father, but were visiting their mother for Christmas.